In stark contrast to the 1st book I read on my trip, I thoroughly enjoyed Don Richardson's 'Eternity in their Hearts.' It's certainly not a new book (published the year I was born), but it may end up being my favorite book of 2007. Basically, it's about 'general revelation,' a subject that interests me to a high degree.
Richardson is a missionary and his book argues that at the root of most ancient folk religions of the world lies a monotheism that has only relatively recently evolved into polytheism. Further, he argues that this remnant of monotheism can and has been utilized by missionaries as a bridge to Christ with fantastic results. Telling one of the stories would probably be a better review, but instead I simply recommend the book to you. If you have a heart for missions, you'll love it. If you don't have a heart for missions, you may by the time you're done reading.